Method of producing a metal strip including a longitudinal channel by roll-form reduction of a multi-gage strip

ABSTRACT

A method of continuously producing a metal strip including a longitudinal channel comprising the steps of rolling a strip of metal to varying thicknesses in which a thick portion is positioned adjacent to a thin portion, and thereafter roll form reducing the strip to substantially change its shape and to reduce substantially the strips&#39;&#39; cross-sectional area.

Umted States Patent 1191 1 11-11 3,850,019 Bray et al. 1 Nov. 26, 1974 [54] METHOD OF PRODUCING A METAL STRIP 674,652 5/1901 Mergler et al. 72/365 INCLUDING A LONGITUDINAL CHANNEL l 33: 2; 3; g g; 354222 o s BY ROLL'FORM REDUCTION OF A 1,656,846 1/1928 Witherow 72/366 MULTl-GAGE STRIP 1,915,084 6/1933 Bonsai] 72/366 [75] Inventors: Robert S. Bray; Claude D. Tapley, 3; g 2 3 both of h hi Conn. ape 3,488,988 1/1970 Laigle et a1. 72/366 [73] Assignee: Anaconda American Brass C0., 3,630,059 1 Henkel 2/199 X W t rb ry C 3,808,863 5/1974 Marcovitch 72/199 [22] Flled: 1972 Primary Examiner-C. W. Lanham [21] Appl, N0.: 310,158 Assistant EXaminer-D, C. Reiley, III

[52] US. Cl 72/199, 29/155 R, 72/366 [57] I ABSTRACT [51] Int. Cl ..B2lb 1/12 A h d f l d l 58 Field of Search 72/365, 366; 29/155 0, 0 99 Y r? meta smp 29/155 72/199 cludmg a 10ng1tud1na1 channel compnsmg the steps of rolling a strip of metal to varying thicknesses in which 56] References Cited a tlgicllj portt ion/is ltlaci sitionetcii acijacergt to a thin pobrtion,

an t erea ter r0 orm re uclng t e stnp to su stan- UNITED STATES PATENTS tially change its shape and to reduce substantially the glarlke 72432686? trips crossectional area ay or et a 450,330 4/1891 Large et a1 72/365 X 4 Claims, 12 Drawing Figures METHOD OF PRODUCING A METAL STRIP INCLUDING A LONGITUDINAL CHANNEL BY ROLL-FORM REDUCTION OF A MULTI-GAGE STRIP BACKGROUND OF THE INVENTION The formation of a metal strip having a multi-gage section has previously been accomplished using extrusion or drawing techniques. A drawback of the extrusion process is that the types of cross-sectional areas that can be satisfactorily produced are limited. A prior proposal has been made to form strips with varying thickness and thereafter bend the strips into enclosed beams (see US. Pat. No. 2,085,829 issued July 6, 1937); however, this proposal relies solely on the use of a bending operation to form the final product and is therefore unsuited for forming many types of shapes.

Products may also be formed using drawing, but this operation is also limited in its application.

SUMMARY OF THE INVENTION It has now been found that by first forming a multigage strip and then using a localized reduction operation in combination with forming techniques that markedly improved results over a wide range of products, shapes and sizes can be attained.

Broadly, the present method comprises rolling metal to produce a multi-gage strip having a thick portion and an adjacent thin portion, thereafter roll-form reducing the strip which roll-form reduction includes substantially changing the shape and substantially reducing the cross-sectional area of the strip. I It is a feature of the method that the strip is shaped by rolling to provide a strip having selected metal distribution such that the strip is formed to the desired shape having desired dimensional tolerances without need for pointing, drawing or annealing.

It is also a feature that the finished strip has a rolled surface unlike extruded or drawn shapes.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a side elevation view of the strip roll-form reduction apparatus;

FIG. 2 is an expanded sectional view along line 22 of FIG. 1;

FIG. 3 is a partial expanded sectional view along line 3-3 of FIG. 1',

FIG. 4 is an expanded sectional view along line 4-4 of FIG. 1.

FIGS. 5 through 8 are cross-sectional views of alternatively shaped strips which are suitable for use in the reducing operation of the present invention and FIG. 5a through 8a illustrate the cross-sections of the strip after such roll-form reduction.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIGS. 1-4, a preferred embodiment of the present method is shown in which a strip 1 has been rolled by any suitable means to provide a crosssectional configuration (see FIG. 2) which includes thick portion 3 and two adjacent thin portions 5 and 7. Thick portion 3, including that area delineated by dimensions A, B, C and D, serves to provide adequate material in corner areas as roll-form reduction is accomplished. Alternatively, strip 1 may have a central thick portion 3' with one adjacent portion of less thickness 5' and another adjacent portion 6 thicker than the central portion (see FIG. 5).

The strip is then fed continuously between work rolls 8 and 10 which simultaneously perform two functions. First, they reshape the strip about an axis parallel to the longitudinal axis of the strip and second, they reduce the cross-sectional area of the strip. Metal movement in various areas, for example, in formed corner areas, such as areas designated 11 in FIG. 3, permit formation of completed strips having the cross-sectional shapes shown in the drawings.

In the roll-form reduction step of the present invention the end portions of the multilayer strip (the left and right hand portions of the sectional views in the drawings) are often reshaped by roll action in such a manner that they are generally bent or rotated away from the center of the thick portions of the strips thus providing substantial amounts of material available for movement when forces of tension are applied. Referring to FIGS. 6 and 6a, material supply area 12 is fed against a roll 10 whose shape has been modified to produce the shape shown in FIG. 6a. Roll 8 (also suitably shaped), in combined action with roll 10, moves the end or side areas of the strip away from area 12 to form the final strip (FIG. 6a). In FIGS. 68, middle and adjacent material areas are designated 12, 13 and 14, respectively.

The amount of cross-sectional area reduction during the roll-form reduction step is substantial but not extensive. The amount of cross-sectional area reduction is held down to the amount required to accommodate for the metal movement associated with the reorganization and reshaping of portions of the strip as shown in the drawings and to the amount required to accomplish reshaping to desired tolerances. Examples of the amount of cross-sectional reduction are found in runs made where the weight per linear inch of the strip before and after roll-form reduction was measured. A multi-gage copper strip having the shape shown in FIG. 2 weighed 15.4 g/inch before final processing and 14.23 g/inch after processing to the shape shown in FIG. 4. This was a reduction in cross-section area of 7.6 percent.

Another copper strip having the shape shown in FIG. 6 was similarly weighed before and after its reduction to a FIG. 6(a) shape. A reduction from 8.69 g/inch to 7.59 g/inch was noted. This is a reduction of 12.7 percent.

Referring to FIGS. 5, 7 and 8, the sectional views of the strip are shown oriented in positions similar to that of FIG. 2. Using suitable shaped rolls 8 and 10, the shape of FIGS. 5a. 7a and 8a are obtained by roll-form reduction. In each case roll 10 causes the end portions to be moved upward, as shown in the drawings, and to be reformed in such a way that a channel is formed in the strip.

The term roll-form reduction as used herein describes the action of rolls which substantially change the shape and, reduce the cross-sectional area of the strip a substantial amount as required to obtain dimensional accuracy of the finished strip. The change in cross-sectional area is not extensive in that it is limited to that necessary to move sufficient material to accomplish dimensional accuracy in the final strip which accuracy for shapes having the cross-sectional areas herein described is plus or minus a few thousands of an inch. The dimensional accuracy obtainable with proper roll design, roll positioning and initial formation of multi-gage strip of proper cross-section is that presently required by industry for metal strips of the cross-sectional areas herein described.

We claim:

1. A method of continuously forming a metal strip including a channel portion comprising 1. rolling a metal strip to varying thicknesses which sectional area of the strip to the extent required to accomplish an acceptable degree of dimensional accuracy in the formed strip whereby a formed strip having a channel configuration is produced.

2. The method of claim 1 in which the multi-gage strip prior to passing it between said pair of rolls has a thickness in its center portion which is less than its thickness on either side of the center portion.

3. The method of claim 1 in which the multi-gage strip prior to passing it between said pair of rolls has a thickness in its center portion which is greater than its thickness on either side of the center portion.

4. The method of claim 1 in which the initial rolling step forms a strip having two spaced-apart areas of greater thickness than the remainder of the strip which areas form the outside corners of the channel portion formed during subsequent passage of the strip between said pair of rolls. 

1. A method of continuously forming a metal strip including a chaNnel portion comprising
 1. rolling a metal strip to varying thicknesses which rolled multi-gage strip has when viewed in a cross section taken perpendicular to the longitudinal axis of the strip portions of substantially different thicknesses and thereafter;
 2. passing the multi-gage strip between a pair of rolls shaped and positioned with respect to one another to reshape the strip through rotating portions of the strip about an axis parallel to the longitudinal axis of the strip so that at least two of said portions are rotated a sufficient distance to form said channel portion and to simultaneously reduce the crosssectional area of the strip to the extent required to accomplish an acceptable degree of dimensional accuracy in the formed strip whereby a formed strip having a channel configuration is produced.
 2. passing the multi-gage strip between a pair of rolls shaped and positioned with respect to one another to reshape the strip through rotating portions of the strip about an axis parallel to the longitudinal axis of the strip so that at least two of said portions are rotated a sufficient distance to form said channel portion and to simultaneously reduce the cross-sectional area of the strip to the extent required to accomplish an acceptable degree of dimensional accuracy in the formed strip whereby a formed strip having a channel configuration is produced.
 2. The method of claim 1 in which the multi-gage strip prior to passing it between said pair of rolls has a thickness in its center portion which is less than its thickness on either side of the center portion.
 3. The method of claim 1 in which the multi-gage strip prior to passing it between said pair of rolls has a thickness in its center portion which is greater than its thickness on either side of the center portion.
 4. The method of claim 1 in which the initial rolling step forms a strip having two spaced-apart areas of greater thickness than the remainder of the strip which areas form the outside corners of the channel portion formed during subsequent passage of the strip between said pair of rolls. 